FIG. 15 shows a conventional optical connector fixing structure. In this structure, an optical connector 102 that is provided on a distal end of an optical fiber 101 is fixed onto a substrate 105 via a package 103 and a connector installation frame 104 (see Patent Document 1).
In the connector 102, signal light is directed downwards by a sloping surface 102a (i.e., a reflective surface), and is directed towards an interface device 106 on the substrate 105.
A pair of guide pin insertion holes 102b are formed in the connector 102. The connector 102 is positioned on the connector installation frame 104 as a result of guide pins 107 that are provided on the connector installation frame 104 being inserted into the guide pin insertion holes 102b. 
A connector holding frame 108 which has guide pin insertion holes 108a is provided on the connector 102. The connector holding frame 108 is screwed to the package 103 with the guide pins 107 in a state of being inserted in the guide pin insertion holes 108a.     Patent document 1: Japanese Patent Application Laid-Open (JP-A) No. 2000-292658